JP2003124445A - Magnetic memory and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic memory wherein a contact film between a TMR multilayer film and an upper interconnection can be formed self-alignedly, and also to provide a method of manufacturing the same. SOLUTION: The magnetic memory comprises the TMR multilayer film (6) formed on a first conductive film (4), and a second conductive film (8) which is formed on the TMR multilayer film (6) and has the same planar shape as the TMR multilayer film. The second conductive film has a flat surface. A first insulation film (10) is so formed as to surround the TMR multilayer film (6) and the second conductive film (8), and has a flat surface having the same height as that of the surface of the second conductive film (8). A second conductive film (12) is formed on the first insulation film (10) and is electrically connected to the second conductive film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic memory device and a manufacturing method thereof.

[0002]

2. Description of the Related Art FIG. 10 shows a conventional method of manufacturing a magnetic memory device. First, as shown in FIG. 10A, a conductive film 104 of Al is formed on the insulating film 102 of SiO2 and patterned. Subsequently, a TMR film (tunnel magnetoresistance film) 106 is deposited on the patterned conductive film 104 and patterned.

Next, as shown in FIG. 10B, an interlayer insulating film 110 is formed on the insulating film 102 so as to cover the first conductive film 104 and the TMR film 106.

Next, as shown in FIG. 10C, a photoresist is applied on the interlayer insulating film 110 to form a resist mask 120 having a contact pattern.

Next, as shown in FIG. 10D, the interlayer insulating film 110 is etched to form a contact hole so that a part of the surface of the TMR film 106 is exposed.

Next, as shown in FIG.
1 wiring layer 108 is deposited. At this time, the wiring layer 10
8 is also formed on the inner surface of the contact hole, so that the wiring on the interlayer insulating film 110 and the upper electrode of the TMR film 106 are connected.

As described above, in the conventional technique, after the interlayer insulating film up to the upper part of the TMR film is removed by dry etching using the patterned resist as a mask,
The upper wiring layer of Al was formed. Thus, TMR
A contact is formed to the top of the membrane.

However, in the above process, the shape of the contact hole is determined by patterning the resist, and it is necessary to prepare a misalignment margin between the TMR film and the contact hole. As a result, T
There is a problem that the contact between the upper portion of the MR film and the upper wiring cannot be formed in a self-aligned manner, and miniaturization is difficult.

Further, since the contact hole is not completely filled in the film formation of the upper wiring layer, the film thickness of the wiring layer in the contact cross section is reduced. As a result, there is a problem that the cross-sectional area of the upper wiring layer becomes small just above the contact and migration due to the write current becomes large.

Further, in order to make contact with the upper part of the TMR film, it is necessary to remove the interlayer insulating film up to the upper part of the TMR film by plasma etching using the patterned resist as a mask. As a result, the TMR film is damaged due to the plasma etching, so that the TMR film is damaged.
There is a problem that the yield of the film is reduced.

In connection with the above description, Japanese Patent Laid-Open No. 2000-20
The 620A publication discloses a magnetic field detecting element. In this reference, the magnetic field detecting element includes a perovskite-type conductive oxide magnetic material electrode, a ferromagnetic metal electrode, and an insulating film. An insulating film is placed between the two electrodes,
Detect the tunnel current. Further, the insulating film has a thickness capable of interrupting exchange magnetic coupling between the two electrodes.

Further, a tunnel magnetoresistive head is disclosed in Japanese Patent Laid-Open No. 2-212058.
No. 000-20620A. In this reference, the tunnel magnetoresistive head has a tunnel barrier layer, a ferromagnetic free layer formed so as to sandwich the tunnel barrier layer, and a tunnel multilayer film in which a ferromagnetic pinned layer is laminated. In this head, a tunnel barrier layer and a nonmagnetic metal protection layer are sequentially formed on a ferromagnetic pinned layer. Side insulating layers are formed on both sides of the stack including the ferromagnetic pinned layer, the tunnel barrier layer and the non-magnetic metal protection layer. The surface of the nonmagnetic metal protect layer is cleaned, and the ferromagnetic free layer is formed so as to face the ferromagnetic pinned layer through the treated surface.

[0013]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a magnetic memory device in which a contact film between a TMR laminated film and an upper wiring can be formed in a self-aligned manner, and a manufacturing method thereof. Is.

Another object of the present invention is to provide a magnetic memory device capable of eliminating plasma damage to the TMR laminated film when etching the interlayer insulating film, and a method of manufacturing the same.

Another object of the present invention is to provide a magnetic memory device and a method of manufacturing the same which can improve the reliability of a data write current to a TMR laminated film.

Another object of the present invention is to provide a magnetic memory device capable of reducing a data write current to a TMR laminated film and a method of manufacturing the same.

Another object of the present invention is to provide a magnetic memory device capable of reducing the wiring width and the wiring interval and achieving high density, and a manufacturing method thereof.

[0018]

[Means for Solving the Problems] Means for solving the problems will be described below with reference to the numbers and symbols used in the embodiments of the present invention. These numbers and signs are added to clarify the correspondence relationship between the description of [Claims] and the description of the embodiments of the invention.
It should not be used to interpret the technical scope of the invention described in [Claims].

In the aspect of the present invention, the magnetic memory device is the first
A TMR laminated film (6) formed on the conductive film (4) and a second conductive film (8) formed on the TMR laminated film (6) and having the same planar shape as the TMR laminated film. To do.

Here, in the magnetic memory device of the present invention, the second conductive film has a flat surface. Further, the magnetic memory device of the present invention is formed so as to surround the TMR laminated film (6) and the second conductive film (8), and is flat at the same height as the surface of the second conductive film (8). A first insulating film having a surface (1
0) and a third conductive film (12) formed on the first insulating film (10) and electrically connected to the second conductive film.

According to another aspect of the present invention, the magnetic memory device is formed on the TMR laminated film (6) formed on the first conductive film (4) and the TMR laminated film (6), A second conductive film (8) having the same planar shape as that of the TMR laminated film (6) and a soft conductive film formed on the second conductive film (8) and having the same planar shape as the second conductive film (8). Magnetic film (2
2) and

In the magnetic memory device of the present invention, it is preferable that the soft magnetic film has a flat surface. At this time, the magnetic memory device of the present invention is formed so as to surround the TMR laminated film (6), the second conductive film (8), and the soft magnetic film (22), and the soft magnetic film ( 22) a first insulating film (10) having a flat surface having the same height as the surface of (22), and electrically connected to the soft magnetic film (22) formed on the first insulating film (10). The third conductive film (12) may be further provided.

In the above magnetic memory device, it is preferable that the first conductive film is connected to one of a source and a drain of a MOS transistor.

Further, according to another aspect of the present invention, a magnetic memory device includes a plurality of transistors (50) formed in a matrix on a substrate and a first transistor (50) formed so as to cover the plurality of transistors (50). 1 interlayer insulating film (52, 54, 58)
And a plurality of first conductive films (4) formed on the plurality of transistors (50) so that only the upper surfaces of the first interlayer insulating films (52, 54, 58) are exposed.
And each of the plurality of first conductive films (4) is connected to one of a drain and a source of the plurality of transistors (50) in a corresponding column, and is formed on each of the plurality of first conductive films. A plurality of magnetic storage elements, and each of the plurality of magnetic storage elements is sandwiched between a corresponding one of the plurality of first conductive films (4) and a second conductive film (8). It has a film (6) and has the same height as the uppermost layer film so as to cover the plurality of first conductive films (4) and expose the upper surfaces of the uppermost layer films of the plurality of magnetic memory elements. A second interlayer insulating film (1) formed on the first interlayer insulating film at a height.
0) and a plurality of third conductive films (12) formed on the second interlayer insulating film (10), and the plurality of third conductive films (12).
Each of the conductive films (12) is electrically connected to the uppermost layer film of each column of the plurality of magnetic memory elements.

Here, in the magnetic memory device of the present invention, each of the plurality of magnetic memory elements includes the corresponding first conductive film, the TMR laminated film, and the second conductive film, and the uppermost layer. The film is the second conductive film. Alternatively, each of the plurality of magnetic memory elements has the corresponding first conductive film, the TMR laminated film, the second conductive film, and the soft magnetic film, and the uppermost film is the soft magnetic film. Is.

Further, according to another aspect of the present invention, in a method for manufacturing a magnetic memory device, a first conductive layer is formed on the first insulating film (2).
A first step of sequentially stacking a TMR laminated layer and a second conductive layer, a second step of patterning the second conductive layer to form a first hard mask, and the TMR using the first hard mask. A third step of patterning the laminated layer and the first conductive layer to form a first conductive film (4);
Patterning the patterned second conductive layer to form a second
Fourth forming second conductive film (8) as hard mask
A step of patterning the patterned TMR laminated layer to form a TMR laminated film (6) using the second hard mask, the first conductive film,
So as to cover the TMR laminated film and the second conductive film,
Forming a second insulating film (10) on the first insulating film;
And a seventh step of removing the second insulating film until the upper surface of the second conductive film is exposed, and the second insulating film after the removal so as to be electrically connected to the second conductive film. An eighth step of forming a third conductive film (12) on the film.

According to another aspect of the present invention, a method of manufacturing a magnetic memory device is characterized in that a first conductive layer and a TMR layer are formed on a first insulating film (2).
A first step of sequentially laminating a laminated layer, a second conductive layer, and a soft magnetic layer; a second step of patterning the soft magnetic layer and the second conductive layer to form a first hard mask; A third step of patterning the TMR laminated layer and the first conductive layer to form a first conductive film (2) using one hard mask, the patterned soft magnetic layer and the patterned soft magnetic layer. The second conductive layer is patterned to form a second
A fourth step of forming a soft magnetic material film (22) and a second conductive film (8) as a hard mask, and patterning the patterned TMR laminated layer using the second hard mask to form a TMR laminated layer. A fifth step of forming a film (6) and a second insulation on the first insulation film so as to cover the first conductive film, the TMR laminated film, the second conductive film, and the soft magnetic film. A sixth step of forming the film (10), a seventh step of removing the second insulating film until the upper surface of the soft magnetic material film is exposed, and an electrical connection with the soft magnetic material film. And an eighth step of forming a third conductive film (12) on the removed second insulating film.

Here, in the method of manufacturing a magnetic memory device according to the present invention, the seventh step is to remove the second insulating film by C.
It is preferable to include the step of MP. The second insulating film is made of SiO2, SiNx, PSG and BPS.
It is preferably formed of a material selected from the group consisting of G.

According to another aspect of the present invention, in a method of manufacturing a magnetic memory device, a first step of sequentially laminating a TMR laminated layer and a conductive layer on a first conductive film (4), and patterning the conductive layer. A second step of forming a second conductive film (8) as a hard mask, and a third step of patterning the TMR laminated layer by using the hard mask to form a TMR laminated film (6); A fourth step of forming an insulating film (10) on the first conductive film so as to cover the first conductive film, the TMR laminated film, and the second conductive film, and the upper surface of the second conductive film is exposed. Until, a fifth step of removing the insulating film, and a sixth step of forming a third conductive film (12) on the removed insulating film so as to be electrically connected to the second conductive film. It is equipped with.

According to another aspect of the present invention, in the method for manufacturing a magnetic memory device, a first step of sequentially laminating a TMR laminated layer, a conductive layer, and a soft magnetic material layer on the first conductive film (4). A second step of patterning the soft magnetic material layer and the conductive layer to form a soft magnetic material film (22) and a second conductive film (8) as a hard mask; and using the hard mask,
The TMR laminated film is patterned to form a TMR laminated film (6)
Forming a first step, the first conductive film, and the TM
A fourth step of forming an insulating film (10) on the first conductive film so as to cover the R laminated film, the second conductive film, and the soft magnetic film, and exposing the upper surface of the soft magnetic film. Until, a fifth step of removing the insulating film, and a sixth step of forming a third conductive film (12) on the removed insulating film so as to be electrically connected to the soft magnetic film. It is equipped with.

Here, in the method of manufacturing a magnetic memory device of the present invention, it is preferable that the fifth step includes a step of CMP the insulating film. The insulating film is preferably formed of a material selected from the group consisting of SiO2, SiNx, PSG and BPSG.

According to another aspect of the present invention, in a method of manufacturing a magnetic memory device, a first step of sequentially stacking a TMR laminated layer and a conductive layer on the first conductive film (4), and the conductive layer are formed. Second conductive film (8) patterned and used as a hard mask
And a third step of forming the TMR laminated film (6) by patterning the TMR laminated layer by using the hard mask and forming the TMR laminated film (6). .

Here, in the method of manufacturing a magnetic memory device of the present invention, the first step includes a step of laminating a soft magnetic layer on the conductive layer, and the second step includes forming the soft layer on the conductive layer. In addition, the step of patterning the soft magnetic layer to form the soft magnetic layer (22) may be included. At this time, the hard mask is composed of the soft magnetic film and the second conductive film, and the uppermost layer is the soft magnetic film.

In the method of manufacturing a magnetic memory device of the present invention, a step of forming a transistor on a substrate, a step of forming an interlayer insulating film as a first insulating film so as to cover the transistor, and the first Through the insulating film,
The method may further include forming a plug that connects the first conductive film to the transistor, and forming the first conductive film as a groove wiring in the second insulating film.

Further, in the method of manufacturing a magnetic memory device of the present invention, the step of forming a third insulating film so as to cover the first conductive film and the uppermost layer, and the step of exposing the upper surface of the uppermost layer, The method may further include the step of CMP the third insulating film, and forming the third conductive film connected to the uppermost layer as a groove wiring in the fourth insulating film.

In the method of manufacturing a magnetic memory device of the present invention, the first conductive film or the third conductive film is A
It is preferably formed of a material selected from the group consisting of 1, Cu, and AlSiCu. The second conductive film is made of TiN, Al, Ti, and Ta / Al.
It is preferably made of a material selected from the group consisting of / Ta.

As described above, in the present invention, the shape processing (milling process or etching process) of the tunnel resistance element (TMR laminated film) is performed using the hard mask. In this way, the TMR laminated film can be formed in a self-aligned manner. Further, the film thickness of the hard mask is set to be almost the same as the film thickness of the interlayer insulating film formed after the shape processing, and the upper part of the hard mask is formed by chemical mechanical polishing (CMP). By being exposed, a contact to the upper part of the TMR laminated film is formed.
This makes it possible to easily and accurately form a contact even if the TMR laminated film is further miniaturized. Further, since it is not necessary to etch the interlayer insulating film by the plasma which has been used conventionally, it is possible to reduce the damage to the TMR laminated film by the plasma. Further, since the wiring on the upper part of the TMR laminated film is formed on the plane, the stability of the write magnetic field and the wiring reliability can be improved. Also, by sandwiching the soft magnetic film between the upper wiring and the TMR, it becomes possible to reduce the current required for writing.

[0038]

BEST MODE FOR CARRYING OUT THE INVENTION The magnetic memory device of the present invention will be described in detail below with reference to the accompanying drawings.

The structure of the magnetic memory device according to the first embodiment of the present invention will be described with reference to FIG.

In FIG. 2D, the first conductive film 4 is formed on a part of the first insulating film 2. As the material of the first insulating film 2, SiO2, SiNx, PSG, BPSG or the like is used. When a Si substrate is used under the insulating film 2, the first insulating film 2 may have a film thickness such that insulation between the first conductive film 4 and the Si substrate is sufficiently obtained.
00 nm or more is used.

Since the first conductive film 4 is used as a lower wiring, the material of the first conductive film 4 is preferably a conductive metal or metal compound. More specifically, Al,
A metal having a low specific resistance value such as Cu or AlSiCu is suitable. The film thickness of the first conductive film 4 is preferably 200 nm to 800 nm in order to secure low wiring resistance and reliability from disconnection.

In the magnetic memory device of the first embodiment, the first
A TMR laminated film 6 is formed on a part of the conductive film 4. The TMR laminated film 6 is 1.5 n from the side close to the insulating film 2.
m Ta layer / 2 nm NiFe layer / 10 nm IrMn layer / 3
nm CoFe layer / 1.5 nm Al2O3 layer / 5 nm NiF
It has a laminated structure of an e layer / 5 nm Ta layer. However, the structure is not limited to this, and the materials and the film thickness of each layer may be appropriately adjusted according to the desired characteristics. Further, the TMR laminated film 6 may be formed on the entire first conductive film 4 instead of a part thereof.

A second conductive film 8 is formed on the TMR laminated film 6.
Are formed so as to have a flat surface. The second conductive film 8 may have the same shape as the TMR laminated film 6. The material of the second conductive film 8 is preferably a conductive metal or metal compound and a laminated film thereof. This is because if the resistance connected in series to the TMR laminated film 6 is large, the resistance change ratio is reduced. More specifically, a TiN film is suitable. Al film, Ti film, Ta / A
An l / Ta laminated film or the like can also be used. When the TiN film is used, the film thickness of the second conductive film 8 is 200 nm to 6 nm.
It is preferably 00 nm. This is because if the film thickness is 200 nm or less, a sufficient margin cannot be obtained in the polishing in the subsequent process, and if the film thickness is 600 nm or more, the distance between the TMR laminated film 4 and the upper wiring becomes long and the write current increases. .

A second insulating film 10 is formed around the first conductive film 4, the TMR laminated film 6 and the second conductive film 8 on the first insulating film 2. The material of the second insulating film 10 is SiO.
2 is used. SiNX, PSG, BPSG, etc. can also be used. The surface of the second insulating film 10 is flattened so as to be substantially the same in height as the surface of the second conductive film 8.

A third conductive film 12 is formed on the flattened surfaces of the second insulating film 10 and the second conductive film 8 so as to establish electrical connection with the second conductive film 8. Since the third conductive film is used as the upper wiring, the material of the third conductive film is preferably a conductive metal or metal compound. More specifically, a metal film having a low specific resistance value such as an Al film, a Cu film, or an AlSiCu film is suitable as the third conductive film. The thickness of the third conductive film is preferably 200 nm to 800 nm in order to secure low wiring resistance and reliability.

Next, a method of manufacturing the magnetic memory device according to the first embodiment of the present invention will be described.

As shown in FIG. 1A, a first conductive film 4 ', a TMR laminated film 6', and a second conductive film 8'are laminated on the first insulating film 2 in this order. In this embodiment, the first insulating film 2 is a SiO2 film and has a film thickness of 200 nm or more. The first conductive film 4'is an Al film and has a thickness of 200 nm
It has a film thickness of 800 nm. The TMR laminated film 6 ′ is a Ta layer of 1.5 nm / NiFe layer of 2 nm from the side close to the insulating film 2.
It has a laminated structure of an IrMn layer of / 10 nm, a CoFe layer of 3 nm, an Al2O3 layer of 1.5 nm, a NiFe layer of 5 nm, and a Ta layer of 5 nm. The second conductive film 8 ′ is a TiN film, and is 20
It has a film thickness of 0 nm to 600 nm.

Next, as shown in FIG. 1B, the first
A photoresist is applied on the laminated film of the conductive film 4 ′, the TMR laminated film 6 ′, and the second conductive film 8 ′, and a resist mask for the lower wiring pattern is formed by using the photolithography technique. Then, the second conductive film 8 ′ which is not covered with the resist mask is removed by etching. In order to accurately form the lower wiring pattern, the etching method is preferably highly anisotropic. More specifically, reactive plasma etching with a chlorine + argon gas is used. A sputtering method using ions such as milling may be used. Subsequently, the resist is ashed by oxygen plasma or removed by an organic chemical.

Next, as shown in FIG. 1C, the second
Using the conductive film 8 ″ as a hard mask, the TMR laminated film 6 ′ and the first conductive film 4 ′ which are not covered with the second conductive film 8 ″ are removed. In order to accurately form the lower wiring pattern, the etching method is preferably highly anisotropic. More specifically, milling is used.
This is because the TMR laminated film 6 is a laminated structure of thin films of different materials, and therefore reactive etching is complicated and difficult.
Reactive etching may be used when the material of the first conductive film 4 ′ is such that reactive etching is relatively easy.

Next, as shown in FIG. 1D, a photoresist is applied again, and TM is deposited on the second conductive film 8 ".
A resist mask having a pattern for the R laminated film 6 ″ is formed. By etching, the portion of the second conductive film 8 ″ not covered by the resist mask is removed. TMR
In order to form the pattern of the laminated film 6 ″ with high accuracy, the etching method is preferably highly anisotropic. More specifically, reactive plasma etching using a gas of chlorine and argon is used. Milling, etc. Alternatively, the resist may be ashed with oxygen plasma or removed with an organic chemical.

Next, as shown in FIG. 2A, the second
Using the conductive film 8 as a hard mask, the TMR laminated film 6 ″ which is not covered with the second conductive film 8 is removed.
The etching method is preferably highly anisotropic. More specifically, milling is used. This is because the TMR laminated film 6 ″ is a laminated structure of thin films of different materials, and thus reactive etching is complicated and difficult.

Next, as shown in FIG. 2B, an interlayer insulating film 10 'is formed on the first insulating film 2 so as to cover the first conductive film 2, the TMR laminated film 6 and the second conductive film 8. Is deposited. A SiO2 film is used as the interlayer insulating film 10 '. By using the high density plasma CVD method or the like, the interlayer insulating film can be formed with good coverage. The surface of the interlayer insulating film is flattened by polishing in a later step. Therefore, the interlayer insulating film 10 'includes the first conductive film 2, the TMR laminated film 6 and the second conductive film 2.
It is formed thicker than the total thickness of the conductive film 8. In the first embodiment, the interlayer insulating film is formed to have a film thickness of 500 nm to 800 nm.

Next, as shown in FIG. 2C, the interlayer insulating film 10 'is surface-polished by the CMP method until the upper portion of the second conductive film 8 as a hard mask appears on the surface.

Next, as shown in FIG. 2D, an Al wiring layer is deposited on the flattened surface. Subsequently, photoresist is applied to form a resist mask for the upper wiring pattern. By etching, the Al wiring film not covered by the resist mask is removed,
The third conductive film 12 is formed. The resist is then ashed with oxygen plasma or removed with an organic chemical. Thus, the third conductive film 12 as the upper wiring is formed. The third conductive film 12 is electrically connected to the second conductive film 8.

According to the first embodiment of the present invention, the TMR
Second contact as a contact between the laminated film 6 and the upper wiring 12
The conductive film 8 can be formed in a self-aligned manner. Also,
Unlike the conventional example shown in FIG. 10, since the interlayer insulating film is not used on the TMR laminated film, plasma damage to the TMR laminated film during etching can be eliminated. Further, it is possible to improve the wiring reliability against the write current to the TMR laminated film.

This is because the hard mask used for etching the TMR laminated film is used as it is for the TMR laminated film 6 and the upper wiring film 1.
This is because it is used as a contact or a plug between the two. Also, since the contact 8 is formed by exposing the upper part of the hard mask by chemical mechanical polishing (CMP), it is not necessary to plasma etch the interlayer insulating film. Furthermore, the cross-sectional area of the Al upper wiring does not decrease even directly above the contact.

Next, a method of manufacturing the magnetic memory device according to the second embodiment of the present invention will be described. The magnetic memory device according to the second embodiment of the present invention has the same structure as that of the first embodiment. Here, TMR on the first conductive film
Only the formation of the laminated film is described, and the first conductive film may be formed in an insulating film shape or may be formed as a groove wiring in the insulating film.

As shown in FIG. 3A, a first conductive film 4'is deposited on the first insulating film 2. In this example,
The first insulating film 2 is a SiO2 film and has a film thickness of 200 nm or more. The first conductive film 4 ′ is an Al film, and is 200
It has a film thickness of nm to 800 nm.

Next, as shown in FIG. 3B, the first
A photoresist is applied on the conductive film 4 ', and a resist mask for the lower wiring pattern is formed by using the photolithography technique. Then, the first conductive film 4 ′ which is not covered with the resist is removed by etching. In order to accurately form the lower wiring pattern, the etching method is preferably highly anisotropic. Reactive etching may be used when the material of the first conductive film 4 ′ is such that reactive etching is relatively easy.

Next, as shown in FIG. 3C, the first
A TMR laminated film 6 ′ and a second conductive film 8 ′ are laminated on the conductive film 4 in this order. In this embodiment, the TMR laminated film 6'is
Is a Ta layer having a thickness of 1.5 nm, a NiFe layer having a thickness of 2 nm, an IrMn layer having a thickness of 10 nm, a CoFe layer having a thickness of 3 nm, and a CoFe layer having a thickness of 3 nm.
1.5 nm Al2O3 layer / 5 nm NiFe layer / 5 nm Ta
It has a laminated structure of layers. The second conductive film 8'is a TiN film and has a film thickness of 200 nm to 600 nm.

Next, as shown in FIG. 3D, a photoresist is applied again, and TMR is formed on the second conductive film 8.
A resist mask having a pattern for the laminated film 6 is formed. By etching, the portion of the second conductive film 8 ′ not covered with the resist mask is removed. In order to form the pattern of the TMR laminated film 6 ′ with high accuracy, it is desirable that the etching method be highly anisotropic. More specifically, reactive plasma etching with a chlorine + argon gas is used. A sputtering method using ions such as milling may be used. Then, the resist is ashed by oxygen plasma or removed by an organic chemical.

Next, as shown in FIG. 4A, the second
Using the conductive film 8 as a hard mask, the TMR laminated film 6 ′ that is not covered with the second conductive film 8 is removed.
The etching method is preferably highly anisotropic. More specifically, milling is used. This is because the TMR laminated film 6 is a laminated structure of thin films of different materials, and thus reactive etching is complicated and difficult.

Next, as shown in FIG. 4B, the interlayer insulating film 10 ′ is formed on the first insulating film 2 so as to cover the first conductive film 2, the TMR laminated film 6 and the second conductive film 8. Is deposited. A SiO2 film is used as the interlayer insulating film. By using the high density plasma CVD method or the like, the interlayer insulating film can be formed with good coverage. The surface of the interlayer insulating film is flattened by polishing in a later step. Therefore, the interlayer insulating film is formed thicker than the total thickness of the first conductive film 2, the TMR laminated film 6 and the second conductive film 8. In the second embodiment,
The interlayer insulating film is formed to have a film thickness of 500 nm to 800 nm.

Next, as shown in FIG. 4C, the second insulating film 10 is surface-polished by the CMP method until the upper portion of the second conductive film 8 as a hard mask appears on the surface.

Next, as shown in FIG. 4D, an Al wiring film is deposited on the flattened surface. Subsequently, photoresist is applied to form a resist mask for the upper wiring pattern. By etching, the wiring film in the portion not covered with the resist mask is removed,
The conductive film 12 is formed. The resist is then ashed with oxygen plasma or removed with an organic chemical. The third conductive film 12 is electrically connected to the second conductive film 8.

Next explained is a magnetic memory device according to the third embodiment of the invention. In the third embodiment, the first
The soft magnetic material film 22 is formed on the second conductive film in the embodiment. The soft magnetic film 22 is magnetized by a magnetic field generated when a current flows through the upper wiring (third conductive film 12). Thus, a magnetic field is generated from the soft magnetic film. The direction of the magnetic field generated by the wiring current on the TMR laminated film,
The direction of the magnetic field generated from the soft magnetic film on the TMR laminated film is reversed, but if the magnetic susceptibility of the soft magnetic film is larger than 1, the magnitude of the magnetic field on the TMR laminated film is It will be bigger than when there is no. As a result, the wiring current required to change the resistance value of the TMR laminated film can be reduced.

Next, a method of manufacturing the magnetic memory device according to the third embodiment of the present invention will be described. The method of manufacturing the magnetic memory device according to the third embodiment is basically the same as that of the first embodiment. Therefore, only the different points will be described in detail.

As shown in FIG. 5A, a first conductive film 4 ', a TMR laminated film 6', a second conductive film 8 ', and a soft magnetic material film 22' are formed on the first insulating film 2. It is laminated in this order.

Next, as shown in FIG. 5B, the first
Photoresist is applied on the laminated film of the conductive film 4 ′, the TMR laminated film 6 ′, the second conductive film 8 ′, and the soft magnetic material film 22 ′, and the resist mask for the lower wiring pattern is formed by using the photolithography technique. It is formed. Then, the soft magnetic material film 22 'and the second conductive film 8'which are not covered with the resist mask are removed by etching. In order to accurately form the lower wiring pattern, the etching method is preferably highly anisotropic. Subsequently, the resist is ashed by oxygen plasma or removed by an organic chemical.

Next, as shown in FIG. 5C, the soft magnetic film 22 "and the second conductive film 8" are used as a hard mask to remove the portion not covered by the second conductive film 8 ". The TMR laminated film 6'and the first conductive film 4'are removed. In order to form the lower wiring pattern with high accuracy, it is desirable that the etching method has a high anisotropy. .

Next, as shown in FIG. 5D, a photoresist is applied again and T is formed on the soft magnetic film 22 ".
A resist mask having a pattern for the MR laminated film is formed. By etching, the soft magnetic material film 22 ″ and the second conductive film 8 ″ which are not covered with the resist mask are removed. In order to form the pattern of the TMR laminated film 6 with high precision, the etching method is preferably highly anisotropic. More specifically, reactive plasma etching with a chlorine + argon gas is used.

Next, as shown in FIG. 6A, using the soft magnetic material film 22 and the second conductive film 8 as a hard mask, the TMR laminated film of the portion not covered with the second conductive film 8 is used. 6 ″ is removed. The etching method is preferably highly anisotropic. More specifically, milling is used.

Next, as shown in FIG. 6B, the interlayer insulating film 10 ′ is formed so as to cover the first conductive film 2, the TMR laminated film 6, the second conductive film 8 and the soft magnetic film 22. 1 is deposited on the insulating film 2. A SiO2 film is used as the interlayer insulating film 10 '. By using the high density plasma CVD method or the like, the interlayer insulating film can be formed with good coverage. In the third embodiment, the interlayer insulating film has a thickness of 500 nm
It is formed to have a film thickness of 800 nm.

Next, as shown in FIG. 6C, the interlayer insulating film 10 'is surface-polished by the CMP method until the upper portion of the second conductive film 8 as a hard mask appears on the surface,
The second insulating layer 10 is formed.

Next, as shown in FIG. 6D, an Al wiring layer is deposited on the flattened surface. Subsequently, photoresist is applied to form a resist mask for the upper wiring pattern. By etching, the Al wiring film not covered by the resist mask is removed,
The third conductive film 12 is formed. The resist is then ashed with oxygen plasma or removed with an organic chemical. Thus, the third conductive film 12 as the upper wiring is formed. The third conductive film 12 is electrically connected to the soft magnetic film 22.

Next explained is a magnetic memory device according to the fourth embodiment of the invention. The magnetic memory device according to the fourth embodiment is different from that of the second embodiment in that a soft magnetic film is formed on the second conductive film.

Next, a method of manufacturing the magnetic memory device according to the fourth embodiment of the present invention will be described. As described above, the magnetic memory device of the fourth embodiment is different from the second embodiment only in that the soft magnetic film is added, and therefore only the different points will be described.

As shown in FIG. 7A, the first conductive film 4 ′ is deposited on the first insulating film 2.

Next, as shown in FIG. 7B, the first
A photoresist is applied on the conductive film 4 ', and a resist mask for the lower wiring pattern is formed by using the photolithography technique. Then, the first conductive film 4 which is not covered with the resist is removed by etching.

Next, as shown in FIG. 7C, the first
On the conductive film 4, the TMR laminated film 6 ', the second conductive film 8', and the soft magnetic material film 22 'are laminated in this order.

Next, as shown in FIG. 7D, a photoresist is applied again, and TM is deposited on the second conductive film 8 '.
A resist mask having a pattern for the R laminated film is formed. By etching, the soft magnetic film 22 'and the second conductive film 8'which are not covered with the resist mask are removed.

Next, as shown in FIG. 8A, using the soft magnetic film and the second conductive film 8 as a hard mask, the TMR laminated film 6 in a portion not covered with the second conductive film 8 is formed. 'Is removed.

Next, as shown in FIG. 8B, a first interlayer insulating film 10 ′ is formed so as to cover the first conductive film 2, the TMR laminated film 6, the second conductive film 8 and the soft magnetic film 22. 1 is deposited on the insulating film 2.

Next, as shown in FIG. 8C, the interlayer insulating film is surface-polished by the CMP method until the upper portion of the uppermost soft magnetic film 22 as a hard mask appears on the surface, and the second The insulating film 10 is formed.

Next, as shown in FIG. 8D, an Al wiring film is deposited on the flattened surface. Subsequently, photoresist is applied to form a resist mask for the upper wiring pattern. By etching, the wiring film in the portion not covered with the resist mask is removed,
The conductive film 12 is formed. The resist is then ashed with oxygen plasma or removed with an organic chemical. In this way, the third conductive film 12 is electrically connected to the soft magnetic film 22.

Next explained is a magnetic memory device according to the fifth embodiment of the invention.

The magnetic memory device of the fifth embodiment is a TMR.
The stacked film is driven by the transistor. Also, TMR
The laminated film is formed on the bit line (first conductive film) of the groove wiring structure.

FIG. 9 shows a case where the TMR element is formed on the substrate on which the transistor is formed. The uppermost layer of the wiring of the transistor portion is used as the lower wiring 4. In this embodiment, after the lower wiring 4 is formed as a groove wiring, the TMR laminated film and the subsequent films are formed. Therefore, etching using the resist mask is performed from the TMR pattern. When the grooved wiring structure is used, the alignment margin between the TMR laminated film and the wiring can be eliminated, so that the wiring width and the wiring interval can be minimized and the density of the device can be increased.

Next, a method of manufacturing the magnetic memory device according to the fifth embodiment will be described.

First, as shown in FIG. 9A, element isolation regions 42 are formed in order to form transistors in a matrix on the silicon substrate 40. A transistor 50 having a source / drain / gate is formed in each element isolation region 42. An interlayer insulating film 52 is formed so as to cover the transistor 50. A connection plug 46 reaching the source region and the drain region of the transistor is formed through the interlayer insulating film 52. A wiring 48 connected to the plug 46 is formed on the interlayer insulating film 52. The transistor, the interlayer insulating film 52, and the connection plug 46 are formed by a conventionally known method.

Next, the interlayer insulating film 5 is formed so as to cover the wiring 48.
4 is formed. Here, the surface of the interlayer insulating film 54 is C
It is preferably flattened by MP. Then, a connection plug 56 penetrating the interlayer insulating film 54 and reaching the wiring 48.
Is formed. The presence of the wiring 48 allows the connection plug 56 to be formed at a different location from the connection plug 46.

Next, the interlayer insulating film 5 is formed on the interlayer insulating film 54.
8 is formed. Subsequently, the interlayer insulating film 58 is patterned into a strip shape. At this time, the connection plug 56 is exposed. Then, a conductive layer for the first conductive film 4 is deposited on the patterned interlayer insulating film 58, and then C is formed so that the conductive layer and the interlayer insulating film 58 have the same thickness.
The conductive layer is polished by MP. In this way, the first conductive film 4 serving as a bit line is formed with a groove wiring structure. Therefore, the interlayer insulating film 58 and the first conductive film 4 have flat surfaces. The first conductive film 4 is connected to the corresponding wiring 48 via the connection plug 56.

The subsequent process is similar to that of the second embodiment. That is, as shown in FIG. 9B, the TMR laminated film and the second conductive film are deposited on the first conductive film 4 and the interlayer insulating film 58. Then, the second conductive film is patterned above the transistor. Thus, the second conductive film 8 as a hard mask is formed. The TMR laminated film is patterned using a hard mask.

Next, as shown in FIG. 9C, an interlayer insulating film is deposited. Then, the interlayer insulating film is polished by CMP until the surface of the second conductive film 8 is exposed.
In this way, the second insulating film 10 is formed.

Next, as shown in FIG. 9D, an interlayer insulating film is formed on the insulating film 10. Subsequently, this interlayer insulating film is patterned into a strip shape. Subsequently, a conductive layer for the third conductive film 12 is deposited on the patterned interlayer insulating film, and then the conductive layer is formed by CMP so that the thickness of the conductive layer and the thickness of the interlayer insulating film become equal. To be polished. Thus, the third conductive film 12 that functions as a word line
Are formed with a groove wiring structure. In addition, the insulating film 60 is formed. Therefore, the interlayer insulating film 60 and the third conductive film 12
Has a flat surface. The third conductive film 12 is connected to the TMR laminated film 6 via the second conductive film 8 as a connection plug.

In the fifth embodiment, the third conductive film 12 is
It is connected to the second conductive film 8. However, as described in the fourth embodiment, the soft magnetic film 22 may be formed on the second conductive film.

The TMR element may be formed directly above the transistor or may be formed at a position slightly deviated from just above the transistor. When the TMR element is formed right above the transistor, the magnetic storage device can be formed with the highest density.

[0098]

As described above, according to the magnetic memory device of the present invention, since the TMR laminated film can be formed in a self-aligned manner with the contact plug, the TMR laminated film should be designed in the minimum size. Is possible.

Since the hard mask for patterning the TMR laminated film is also used as the wiring, the reliability of the wiring can be increased.

Further, since no interlayer insulating film is formed on the TMR laminated film, plasma damage to the TMR laminated film can be eliminated.

When the soft magnetic film is formed on the second conductive film, the wiring current for writing can be reduced.

[Brief description of drawings]

1A to 1D are cross-sectional views showing a method of manufacturing a magnetic memory device according to a first embodiment of the present invention.

2A to 2D are cross-sectional views showing a method of manufacturing the magnetic memory device according to the first embodiment of the present invention.

3A to 3D are sectional views showing a method of manufacturing a magnetic memory device according to a second embodiment of the present invention.

4A to 4D are cross-sectional views showing a method of manufacturing a magnetic memory device according to a second embodiment of the present invention.

5A to 5D are cross-sectional views showing a method of manufacturing a magnetic memory device according to a third embodiment of the present invention.

6A to 6D are cross-sectional views showing a method of manufacturing a magnetic memory device according to a third embodiment of the present invention.

7A to 7D are sectional views showing a method of manufacturing a magnetic memory device according to a fourth embodiment of the present invention.

8A to 8D are cross-sectional views showing a method of manufacturing a magnetic memory device according to a fourth embodiment of the present invention.

9A to 9D are perspective views showing a method of manufacturing a magnetic memory device according to a fifth embodiment of the present invention.

10A to 10E are cross-sectional views showing a conventional method of manufacturing a magnetic memory device.

[Explanation of symbols]

2: Insulation film 4: First conductive film (lower wiring) 6: TMR laminated film 8: Second conductive film (connection plug) 10: Second insulating film 12: Third conductive film (upper wiring) 22: Soft magnetic film

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kuniko Kikuta             5-7 Shiba 5-1, Minato-ku, Tokyo NEC Corporation             Inside the company F term (reference) 5F083 FZ10 GA05 GA09 JA36 JA37                       JA39 JA40 JA56 KA20 MA02                       MA06 MA16 MA19 MA20 PR03                       PR04 PR07 PR29 PR40

Claims (22)

[Claims] 1. A magnetic memory device comprising: a TMR laminated film formed on a first conductive film; and a second conductive film formed on the TMR laminated film and having the same planar shape as the TMR laminated film. 2. The magnetic memory device according to claim 1, wherein the second conductive film has a flat surface and is formed so as to surround the TMR laminated film and the second conductive film. A first insulating film having a flat surface having the same height as the surface of the film; and a third conductive film formed on the first insulating film and electrically connected to the second conductive film. Magnetic storage device. 3. A TMR laminated film formed on a first conductive film, a second conductive film formed on the TMR laminated film and having the same planar shape as the TMR laminated film, and on the second conductive film. And a soft magnetic film having the same planar shape as that of the second conductive film. 4. The magnetic memory device according to claim 3, wherein the soft magnetic film has a flat surface, and surrounds the TMR laminated film, the second conductive film, and the soft magnetic film. A first insulating film which is formed and has a flat surface having the same height as the surface of the soft magnetic film; and a first insulating film which is formed on the first insulating film and is electrically connected to the soft magnetic film. A magnetic memory device further comprising: a conductive film. 5. The magnetic memory device according to claim 1, wherein the first conductive film is connected to one of a source and a drain of a MOS transistor. 6. A plurality of transistors formed in a matrix on a substrate, a first interlayer insulating film formed so as to cover the plurality of transistors, and only an upper surface of the first interlayer insulating film is exposed from the first interlayer insulating film. Thus, each of the plurality of first conductive films formed on the plurality of transistors and each of the plurality of first conductive films is connected to one of a drain and a source of the plurality of transistors in a corresponding column. A plurality of magnetic storage elements formed on each of the plurality of first conductive films, and each of the plurality of magnetic storage elements corresponds to a corresponding one of the plurality of first conductive films and a second conductive film. A TMR laminated film sandwiched between the uppermost layer film and the uppermost layer film so as to cover the plurality of first conductive films and expose the upper surfaces of the uppermost layer films of the plurality of magnetic memory elements. On the first interlayer insulating film at the same height as A second interlayer insulating film formed, and a plurality of third conductive films formed on the second interlayer insulating film, wherein each of the plurality of third conductive films is the plurality of magnetic memory elements. Magnetic storage device electrically connected to the top layer film of each row of. 7. The magnetic memory device according to claim 6, wherein each of the plurality of magnetic memory elements includes the corresponding first conductive film, the TMR laminated film, and the second conductive film, A magnetic memory device in which the uppermost layer film is the second conductive film. 8. The magnetic memory device according to claim 6, wherein each of the plurality of magnetic memory elements includes the corresponding first conductive film, the TMR laminated film, the second conductive film, and a soft magnetic film. A magnetic memory device, wherein the uppermost layer film is the soft magnetic film. 9. A first step of sequentially stacking a first conductive layer, a TMR laminated layer, and a second conductive layer on a first insulating film, and patterning the second conductive layer to form a first hard mask. And a second step of forming the first conductive film by patterning the TMR laminated layer and the first conductive layer using the first hard mask, and the patterned second conductive layer. Second by patterning
A fourth step of forming a second conductive film as a hard mask; a fifth step of patterning the patterned TMR laminated layer by using the second hard mask to form a TMR laminated film; A sixth step of forming a second insulating film on the first insulating film so as to cover the first conductive film, the TMR laminated film, and the second conductive film; and until the upper surface of the second conductive film is exposed. A seventh step of removing the second insulating film, and an eighth step of forming a third conductive film on the removed second insulating film so as to be electrically connected to the second conductive film. A method of manufacturing a magnetic memory device, comprising: 10. A first conductive layer, a TMR laminated layer, a second conductive layer, and a soft magnetic layer are sequentially laminated on a first insulating film.
A step of patterning the soft magnetic layer and the second conductive layer to form a first hard mask, and patterning the TMR laminated layer and the first conductive layer using the first hard mask And a second step of patterning the patterned soft magnetic layer and the patterned second conductive layer to form a first conductive film and a second soft mask as a second hard mask. A fourth step of forming a conductive film; a fifth step of patterning the patterned TMR laminated layer by using the second hard mask to form a TMR laminated film; the first conductive film and the TMR; Laminated film, the second conductive film,
And a sixth step of forming a second insulating film on the first insulating film so as to cover the soft magnetic film, and removing the second insulating film until the upper surface of the soft magnetic film is exposed. A method of manufacturing a magnetic memory device, comprising: a seventh step; and an eighth step of forming a third conductive film on the removed second insulating film so as to be electrically connected to the soft magnetic film. 11. The method of manufacturing a magnetic memory device according to claim 9, wherein the seventh step includes a step of CMP the second insulating film. 12. The method of manufacturing a magnetic memory device according to claim 9, wherein the second insulating film is SiO2, SiNx, PSG and BP.
A method of manufacturing a magnetic memory device formed of a material selected from the group consisting of SGs. 13. A first step of sequentially laminating a TMR laminated layer and a conductive layer on a first conductive film, and a second step as a hard mask by patterning the conductive layer.
A second step of forming a conductive film; a third step of patterning the TMR laminated layer by using the hard mask to form a TMR laminated film; the first conductive film, the TMR laminated film, and the A fourth step of forming an insulating film on the first conductive film so as to cover the second conductive film; a fifth step of removing the insulating film until the upper surface of the second conductive film is exposed; And a second step of forming a third conductive film on the removed insulating film so as to be electrically connected to the conductive film. 14. A first step of sequentially stacking a TMR laminated layer, a conductive layer, and a soft magnetic material layer on a first conductive film, and patterning the soft magnetic material layer and the conductive layer to form a soft mask as a hard mask. A second step of forming a magnetic film and a second conductive film; a third step of patterning the TMR laminated layer by using the hard mask to form a TMR laminated film; the first conductive film and the TMR; Laminated film, the second conductive film,
And a fourth step of forming an insulating film on the first conductive film so as to cover the soft magnetic film, and a fifth step of removing the insulating film until the upper surface of the soft magnetic film is exposed. A sixth step of forming a third conductive film on the removed insulating film so as to be electrically connected to the soft magnetic film, the method of manufacturing a magnetic memory device. 15. The method of manufacturing a magnetic memory device according to claim 13, wherein the fifth step includes a step of CMP the insulating film. 16. The method of manufacturing a magnetic memory device according to claim 13, wherein the insulating film is SiO2, SiNx, PSG or BPSG.
A method of manufacturing a magnetic memory device formed of a material selected from the group consisting of: 17. A first step of sequentially laminating a TMR laminated layer and a conductive layer on a first conductive film, and a second step as a hard mask by patterning the conductive layer.
A magnetic layer comprising a second step of forming a conductive film and a third step of forming the TMR laminated film by patterning the TMR laminated layer by using the hard mask and using the hard mask. Storage device manufacturing method. 18. The method of manufacturing a magnetic memory device according to claim 17, wherein the first step includes a step of stacking a soft magnetic layer on the conductive layer, and the second step includes the conductive layer. In addition to the layers, the method includes patterning the soft magnetic material layer to form a soft magnetic material film, the hard mask includes the soft magnetic material film and the second conductive film, and the uppermost layer is the soft magnetic material layer. A method of manufacturing a magnetic memory device which is a magnetic film. 19. The method of manufacturing a magnetic memory device according to claim 17, wherein a step of forming a transistor on a substrate, and a step of forming an interlayer insulating film as a first insulating film so as to cover the transistor. And forming a plug that passes through the first insulating film and connects the first conductive film to the transistor, and forming the first conductive film as a trench wiring in a second insulating film. A method of manufacturing a magnetic storage device further comprising. 20. The method of manufacturing a magnetic memory device according to claim 17, further comprising: forming a third insulating film so as to cover the first conductive film and the uppermost layer; The third insulating film is C until the upper surface of the upper layer is exposed.
A method of manufacturing a magnetic memory device, further comprising: a step of MP and a step of forming a third conductive film connected to the uppermost layer as a groove wiring in a fourth insulating film. 21. The method of manufacturing a magnetic memory device according to claim 9, wherein the first conductive film or the third conductive film is Al, Cu,
And a method of manufacturing a magnetic memory device formed of a material selected from the group consisting of AlSiCu. 22. The method of manufacturing a magnetic memory device according to claim 9, wherein the second conductive film is TiN, Al, Ti, and Ta / A.
A method of manufacturing a magnetic memory device formed of a material selected from the group consisting of 1 / Ta.